As a follow up to the man dying in police custody question, other than civil action, can the DA's decision to not prosecute be appealed for possible prosecution of the officers? If so, to whom?
No. The DA has full discretion. DA refusal should tell you something about the questionable validity of your allegations and claims, or at least the defenses available to the police.
I didn't read the original question but I disagree with Mr. Nelson. The DA rarely prosecutes deaths of people in police custody. It will be up to the family members to pursue a civil rights lawsuit.